Technical Field
The present invention relates to a substrate buffing technology.
Background Art
In the manufacture of a semiconductor device, a chemical mechanical polishing (CMP) apparatus that polishes a surface of a substrate is known. A substrate processing system including the CMP apparatus includes a polishing unit (CMP unit) for performing substrate polishing processing, a cleaning unit for performing substrate cleaning processing and drying processing, a loading/unloading unit for delivering a substrate to the polishing unit and receiving the substrate cleaned and dried by the cleaning unit, and the like. In the polishing unit, a polishing pad is stuck to an upper surface of a polishing table, and a polishing surface is formed. The polishing unit presses a polishing target surface of the substrate held by a top ring to the polishing surface, and rotates the polishing table and the top ring while supplying slurry as a polishing liquid to the polishing surface. Thus, the polishing surface and the polishing target surface are slidably and relatively moved, and the polishing target surface is polished. Further, the applicant has applied for additionally polishing the substrate slightly and cleaning it by providing a finishing processing unit that presses a contact member smaller in diameter than the substrate to the substrate after being polished and relatively moving it, inside the CMP apparatus separately from a main polishing unit (Japanese Patent Laid-Open No. 8-71511).
Also, the CMP apparatus sometimes includes a buffing unit for performing buffing to a processing object. The buffing unit includes a buff table for installing the processing object, and a buff head to which a buff pad smaller in diameter than the processing object is attached, and performs buffing to the processing object by bringing the buff pad into contact with the processing object and relatively moving it. Here, in order to uniformize a buffing state, it is needed to control a contact state of the buff pad to the processing object.
In this respect, in prior art, a technology of pressurizing a pad to the processing object using an elastic member is disclosed. That is, in the prior art, the pad is attached to the elastic member, an end of the elastic member is held, and a space is formed on a side where the pad is not attached of the elastic member. Then, in the prior art, by injecting a fluid to the space and bending the elastic member to a processing object side, the pad is pressurized to the processing object.
Also, for the purpose of removing polishing liquid and polishing residual or the like on a surface of the processing object after polishing processing, the CMP apparatus is sometimes provided with a processing unit including a table for installing the processing object, a head to which a pad with a diameter smaller than that of the processing object is attached, and an arm that holds the head and is horizontally moved within a processing object surface. The processing unit performs predetermined processing to the processing object by bringing the pad into contact with the processing object and relatively moving it.
As described in Japanese Patent Laid-Open No. 2001-310254, the processing unit sometimes includes a grindstone for chamfering the pad. For the grindstone, a part to be in contact with a corner of the pad is formed into a curved surface of a predetermined curvature. By pressing the corner of the pad to the curved surface of the grindstone while rotating the pad, the processing unit chamfers the corner of the pad.